Transistors are known from the publication “SiGe Bipolar Technology for Mixed Digital and Analog RF Applications,” J. Böck et al., IEEE 2000, in which the base layer has an intrinsic segment and an extrinsic segment, where the extrinsic segment connects a base contact with the intrinsic segment. The extrinsic segment has a relatively low boron doping, so that the known transistor has the disadvantage of a high resistance in the base layer. This leads to a drop in power amplification already at low frequencies, and thereby to an effective slow-down of the transistor. In addition, the higher base feed resistance causes greater noise.